Question

When electrodes are used to record the electrocardiogram, an electrolyte gel is usually put between them and the surface of the skin. This makes it possible for the metal of the electrode to form metallic ions that move into the electrolyte gel. Often, after prolonged use, this electrolyte gel begins to dry out and change the characteristic of the electrodes. Draw an equivalent circuit for the electrode while the electrolyte gel is fresh. Then discuss and illustrate the way you expect this equivalent circuit to change as the electrolyte gel dries out. In the extreme case where there is no electrolyte gel left, what does the equivalent circuit of the electrode look like

Answer 1

Answer:

The equivalent circuit for the electrode while the electrolyte gel is fresh

From the uploaded diagram the part A is the electrolyte, the part part B is the electrolyte gel when is fresh and the part C is the surface of the skin

Now as the electrolyte gel start to dry out the resistance $R_s$ of the gel begins to increase and this starts to limit the flow of current . Now when the gel is then completely dried out  the resistance of the gel $R_s$ then increases to infinity  and this in turn cut off flow of current.

The diagram illustrating this is shown on the second uploaded image

Explanation: